DESCRIPTION (provided by investigator): Patient reported physical function is an important component of clinical and epidemiological studies. The traditional instruments used to assess Physical Function have served us well over three decades, but the newer tools of item response theory and computerized adaptive testing now permit major improvements resulting in better power and precision. Our work with the Patient Reported Outcome Measurement Information System (PROMIS) resulted in more powerful patient reported tools. However, this work has revealed critical yet unresolved issues- issues that we address in the current application. We have four specific aims: 1. To develop, test, and extend the PROMIS physical function domain (ability to perform) to assess above normal or superior abilities (positive health) and far below normal abilities (severely impaired, frail). We will also add the new physical function domains of Actual Performance, Satisfaction with physical function Abilities, and Physical Ability for Social Participation, as well as the referent domains of Pain and Global Health. 2. To validate these domains in rheumatoid arthritis, osteoarthritis, lupus, scleroderma, juvenile arthritis, vasculitis, and gout patients, in frailty/aging, nursing home, and positive health populations, as well as populations that may become available through other PROMIS primary research sites (e.g., COPD and Heart Failure). Validation will include responsiveness testing and exploration of differential item function (with age, gender, ethnicity, and disease duration). We will develop and validate short-forms and GAT applications for the extended and new domains. 3. To develop and validate a PRO Drug Safety domain supplemented by medical record review and National Death Index-based mortality surveillance. 4. To encourage use of PROMIS tools by academic investigators, NIH, industry, the Food and Drug Administration, Clinical Research Organizations, and other stakeholders in clinical research. Availability of these tools will result in outcome assessment tools that will not be bounded by floors and ceilings, will be appropriate endpoints for the interventions being studied, will better represent the patient's perspective, and will enable more effective and more cost- effective clinical research.